/*******************************************************************************

  * Copyright (c) 2009 Ketan Padegaonkar and others.

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

  * which accompanies this distribution, and is available at

  * http://www.eclipse.org/legal/epl-v10.html

  *

  * Contributors:

  *     Ketan Padegaonkar - initial API and implementation

  *******************************************************************************/

 package org.eclipse.swtbot.swt.finder.keyboard;

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.StringReader;

 import java.net.URL;

 import org.eclipse.jface.bindings.keys.KeyStroke;

 import org.eclipse.jface.bindings.keys.ParseException;

 import org.eclipse.swt.SWT;

 import org.eclipse.swtbot.swt.finder.utils.BidiMap;

 import org.eclipse.swtbot.swt.finder.utils.FileUtils;

 import org.eclipse.swtbot.swt.finder.utils.SWTBotPreferences;

 /**

  * Allows mapping of characters to {@link KeyStroke}s based on keyboard layouts.

  * 

  * @author Ketan Padegaonkar <KetanPadegaonkar [at] gmail [dot] com>

  * @version $Id$

  */

 class KeyboardLayout {

         private final BidiMap<Character, KeyStroke>        keyStrokes        = new BidiMap<Character, KeyStroke>();

         private final String                                                layoutName;

         private KeyboardLayout(String name, URL resource) throws IOException {

                 this.layoutName = name;

                 initialiseDefaults();

                 parseKeyStrokes(resource);

         }

         public String toString() {

                 return layoutName + " keyboard layout";

         }

         /**

          * Returns the keystroke for typing the specified character.

          * <p>

          * E.g. 'T' will correspond to SHIFT+T. 't' will correspond to 'T'. '!' will correspond to SHIFT+1 on the US

          * keyboard.

          * </p>

          * 

          * @param ch a character.

          * @return the keystroke applicable corresponding to the character.

          */

         public KeyStroke keyStrokeFor(char ch) {

                 KeyStroke keyStroke = keyStrokes.getValue(ch);

                 if (keyStroke != null) {

                         return keyStroke;

                 }

                 throw new IllegalArgumentException("no stroke available for character '" + ch + "'");

         }

         public char toCharacter(KeyStroke key) {

                 Character ch = keyStrokes.getKey(key);

                 if (ch == null)

                         ch = (char) key.getNaturalKey();

                 return ch;

         }

         /**

          * @return the default keyboard layout.

          * @see SWTBotPreferences#KEYBOARD_LAYOUT

          */

         public static KeyboardLayout getDefaultKeyboardLayout() {

                 return getKeyboardLayout(SWTBotPreferences.KEYBOARD_LAYOUT);

         }

         /**

          * @param layoutName the layout of the keyboard.

          * @return the keyboard layout corresponding to the specified layout.

          */

         public static KeyboardLayout getKeyboardLayout(String layoutName) {

                 ClassLoader classLoader = KeyboardLayout.class.getClassLoader();

                 URL configURL = classLoader.getResource(toFolder(myPackage() + "." + layoutName) + ".keyboard");

                 if (configURL == null)

                         configURL = classLoader.getResource(toFolder(layoutName) + ".keyboard");

                 if (configURL == null)

                         throw new IllegalArgumentException(layoutName + ".keyboard not found, see http://wiki.eclipse.org/SWTBot/Keyboard_Layouts for more information.");

                 try {

                         return new KeyboardLayout(layoutName, configURL);

                 } catch (IOException e) {

                         throw new IllegalStateException("could not parse " + layoutName + " keyboard layout properties");

                 }

         }

         private static String myPackage() {

                 return KeyboardLayout.class.getPackage().getName();

         }

         private static String toFolder(String layoutName) {

                 return layoutName.replaceAll("\\.", "/");

         }

         private void initialiseDefaults() {

                 for (char ch = '0'; ch <= '9'; ch++) {

                         keyStrokes.put(ch, KeyStroke.getInstance(0, ch));

                 }

                 for (char ch = 'A'; ch <= 'Z'; ch++) {

                         keyStrokes.put(Character.toLowerCase(ch), KeyStroke.getInstance(0, ch));

                         keyStrokes.put(ch, KeyStroke.getInstance(SWT.SHIFT, ch));

                 }

                 keyStrokes.put('\n', KeyStroke.getInstance(0, '\n'));

                 keyStrokes.put('\r', KeyStroke.getInstance(0, '\n'));

                 keyStrokes.put('\t', KeyStroke.getInstance(0, '\t'));

                 keyStrokes.put('\b', KeyStroke.getInstance(0, '\b'));

                 keyStrokes.put(' ', KeyStroke.getInstance(0, ' '));

         }

         private void parseKeyStrokes(URL resource) throws IOException {

                 String contents = FileUtils.read(resource);

                 BufferedReader in = new BufferedReader(new StringReader(contents));

                 parseKeyStrokes(in);

         }

         private void parseKeyStrokes(BufferedReader in) throws IOException {

                 String line;

                 while ((line = in.readLine()) != null) {

                         char ch = line.charAt(0);

                         String keyStrokeSpec = line.substring(2).replaceAll(" \\+ ", "+");

                         try {

                                 keyStrokes.put(ch, KeyStroke.getInstance(keyStrokeSpec));

                         } catch (ParseException e) {

                                 throw new RuntimeException(e);

                         }

                 }

         }

 }